/Engine/Source/Runtime/AnimationCore/Public/BoneWeights.h
The threshold value at or above which a 0-1 normalized bone weight value will be stored as a non-zero value after scaling and quantizing to a 16-bit integer
namespace UE { namespace AnimationCore { static constexpr float UE::AnimationCore::BoneWeightThreshold = InvMaxRawBoneWeightFloat; } }